A critical review on graphitic carbon nitride-based electrodes in microbial fuel cells for bioelectricity generation and bioremediation

Microbial fuel cell (MFC) has emerged as an auspicious technology among the microbial electrochemistry community in bioelectricity production and bioremediation. Despite the success of MFC technology at laboratory scale, its power output remains insufficient for industrial-scale applications. Scaling up to meet energy demands requires the installation of numerous MFC units, significantly increasing costs due to the need for high-quality electrode materials. The unique features of graphitic carbon nitride (g-C₃N₄), such as its biocompatibility, chemical robustness in aqueous systems, and tunable redox-active structure, make it particularly attractive for enhancing electrode performance in microbial fuel cells. Herein, we provide a critical analysis of g-C₃N₄’s catalytic properties in relation to the specific selection criteria for highly efficient anode and cathode materials. Following this, we delve into g-C₃N₄-based photo- and electrocatalysts for anode and cathode operations such as bioenergy generation, oxygen reduction reaction (ORR), and pollutant removal. Specifically, a myriad of g-C₃N₄-based materials such as g-C₃N₄ composites, g-C₃N₄/single atom catalysts, g-C₃N₄/metal oxides, and g-C₃N₄/metal organic frameworks are discussed extensively, with an emphasis on the material’s structure-performance relationship in MFCs. Moreover, the review highlights the strengths of computational tools like density functional theory (DFT) in catalyst design by bridging computational and experimental results. Finally, we conclude by offering future perspectives on the precise design and fabrication of g-C₃N₄-based materials tailored for MFC applications.